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This is a high quality, short term course of live cultures. 'One week flat' from OptiBac Probiotics is gluten free and therefore may be especially suitable for those with bloating.

Vegetarian Vegetarian
No Gluten No Gluten
Suitable during Pregnancy Suitable during Pregnancy

What's it for?

A natural bacteria supplement from OptiBac Probiotics to be taken for 7 consecutive days.

Who's it for?

For those seeking a high quality, short-term live cultures supplement.

Each sachet:

Provides 5 billion live cultures + 0.3g FOS fibres.

OptiBac Probiotics 'One week flat'

'One week flat' is a food supplement containing natural bacteria (live cultures), in powdered sachets to be taken daily as a one-week course. This can be taken once a month, or as frequently as desired. Please scroll to the bottom of the page to read reviews from our customers who have tried this supplement.

Lactococcus lactis Rosell-1058

More about 'One week flat'

Lactobacillus acidophilus Rosell-52: acidophilus is a natural resident of the intestinal microflora; this strain of acidophilus from OptiBac Probiotics has been shown to survive gastric acidity and biliary salts, and to reach the intestines without damage.

Bifidobacterium bifidum Rosell-71: In-vitro tests suggest that this strain flourishes well with Fructooligosaccharides.

Lactobacillus casei Rosell-215 is of an extensively studied species naturally residing in the intestinal flora; this strain from OptiBac Probiotics has been researched in its ability to resist gastric acidity and bile salts in order to reach your small and large intestines alive.

Lactococcus lactis Rosell-1058 is extracted from the kefir culture, and has been scientifically proven to reach the gut alive.

Fructooligosaccharide fibres (FOS) predominantly settle in the large intestine where they may act as a food source to stimulate the growth of your body's natural bacteria.

This 7 day course is ideal for those looking for a short term, high quality natural bacteria supplement.

Background information

Unlike similar foods and supplements containing live cultures, 'One week flat' is free from added sugars and does not contain gluten, and may therefore be suitable for those with bloating. Abdominal or stomach bloating is thought to be associated with food intolerances, constipation, over-eating, PMS or intestinal gas; leaving the abdomen feeling uncomfortable, full and tight. If you have poor digestion, waste materials and the gases they produce can remain in the gut for long periods of time, often at high temperatures and pressures. This causes bloating and stretching of the gut walls beyond their comfortable limits. An imbalance of bacteria in the gut may result in poor digestive health, bloating, production of smelly and uncomfortable gases, and sluggish bowels. This imbalance is known as dysbiosis.

Healthcare professionals can see Scientific Research on live cultures and bloating.

Please note: As of May 2014, this product has a new name ('One week flat') in the EU. The ingredients remain the same.


As a natural food supplement 'One week flat' can be given to adults and children from 4 years old & up, with the following recommendations: Take one sachet daily with breakfast for a 7 day course, or as professionally directed.

We highly recommend you take 'One week flat' for 7 consecutive days. Most customers take this course once a month, but it can taken as often as desired. For more information see our FAQ: How often should I take OptiBac 'One week flat'?

For best results:

  1. Pour an inch of water into a tall glass, leaving plenty of room for swirling.
  2. Shake the sachet well before gently sprinkling in the powder.
  3. Leave powder to dissolve naturally.
  4. Vigorously swirl the water around in the glass.
  5. Drink, wait, and enjoy the benefits!


Live cultures are not recommended for those with serious medical conditions eg. those who are severely immunosuppressed, have pancreatitis, are in the ICU, have melaena, have a central venous catheter, infants with short bowel syndrome, or to patients with open wounds following major surgery; unless under a doctor's care. Furthermore, pregnant or breastfeeding women should consult their doctor before taking Saccharomyces boulardii, 'For travelling abroad', or natural plant extracts as in 'For daily immunity'.

Nutritional Information

Stabiliser: Maltodextrin; Fructooligosaccharides (FOS); live cultures: (Lactococcus lactis Rosell-1058, Lactobacillus casei Rosell-215, Lactobacillus acidophilus Rosell-52 and Bifidobacterium bifidum Rosell-71).

Each sachet guarantees 5 billion micro-organisms + 0.3g FOS fibres.


Like the rest of the OptiBac Probiotics range, this product does not require refrigeration.

Store away from direct sunlight.

Delivery Options

United Kingdom

Delivery within the United Kingdom and Northern Ireland has a fixed price, regardless of the size and weight of your order. Delivery times are estimates and not guaranteed unless otherwise stated.

Method Price
Standard Shipping
Please allow 4-7 days for delivery.

First Class Postage
Please allow 1-3 days for delivery.

Next Day Courier
Guaranteed delivery next working day if you order by 3pm Monday to Friday (requires signature).



We ship to virtually all countries around the world, with the notable exception of Hong Kong.

Most international delivery prices are dependent on the size of your order and where it's being sent. You'll be shown the final price of shipping in the checkout, before payment, once we have your address and order details.

Please note that not all services are available to all destinations. See our International Delivery Coverage table for the availability of each service for your country.

Method Price
International Standard
Please allow 3-7 days for delivery within Europe and 5-12 days to all other destinations. (Does not include tracking).
International Signed
International postage with delivery confirmation (requires signature).
Please allow 3-7 days for delivery within Europe and 5-12 days to all other destinations.
International Tracked & Signed
International delivery with full tracking and delivery confirmation (requires signature).
Please allow 3-7 days for delivery within Europe and 5-12 days to all other destinations.
International Express Courier
Fast international courier service with full tracking and delivery confirmation (requires signature). Delivers to USA and most other countries in 1-5 days. See our International Delivery Coverage for the delivery time to your country.

Remember: the price of international delivery depends on the size of the order and the country to which it's being sent. The final price of shipping will be shown in the checkout before you pay.

  • I've always had a problem with bloating and had to be careful with food that I'm eating. I felt BIG difference after taking one week flat and finally my tummy feels like it's empty!
    I would definitely recommend to get the confidence back!

    United Kingdom
  • I've had a bloated and uncomfortable stomach for years and has never properly gone away. I was hoping there would be at least one product to make it finally stop, I'm wondering if I'll have to just put up with it and remain unhappy and uncomfortable. This did not work.

  • I came across this as I was searching the web on how I could try and beat my bloating. I've had IBS for about a year and I cannot tell you how unhappy it made me, literally everything I ate made me bl... Read more

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